Policy 3 points traffic To = HUB1-VPN1, which is an SD-WAN member interface. In SD-WAN you must reference the SD-WAN zone (the logical interface) in policies, not its member tunnels. Change the policy’s To interface to the zone HUB1, and the install will succeed.

The SD-WAN rule (config service edit 1) is configured with set mode priority. This means the rule selects the best interface based on a defined performance metric, as opposed to a simple static priority or SLA. The event log (image_41cfb5.png) shows Metric latency and Message Service prioritized by performance metric will be redirected in sequence order. This indicates that the rule is using latency to determine the preferred member. Given that the log message is about a change, and the most logical reason for a change in a priority mode is that a different member is now the best performer, it implies that the latency on port2 has become lower than that on port1.

The log message Service prioritized by performance metric will be redirected in sequence order confirms that FortiGate is changing the member being used for this service. Because the mode is priority, FortiGate dynamically selects the member that currently meets the best performance criteria, which in this case is latency. The log implies a new member has been selected as the most optimal, and with the default configuration, the members are sorted based on their performance, so the outgoing interface list is effectively updated to prefer the new best-performing member (port2).

From the Underlay and network advertisement configuration exhibit for the Secondary HUB :

Under Underlay , the template explicitly lists:

WAN Underlay 1 = port1

WAN Underlay 2 = port2

In FortiManager SD-WAN Overlay Orchestrator, underlay interfaces selected for a hub are the transports used to build the overlay IPsec tunnels (one overlay per underlay, per peer as defined by the template). Because both port1 and port2 are configured as underlays, FortiManager will build overlay tunnels over both underlay links. That supports:

Option C (overlay tunnel on port1 )

Option B (overlay tunnel on port2 )

For the BGP neighbor options:

The Network Advertisement section shows Interface 1 = port5 , which indicates a LAN/internal interface whose connected or static networks may be advertised into the overlay routing domain. This does not make port5 a BGP neighbor interface; it is the interface whose routes are being advertised.

The template indicates Dynamic BGP is enabled. In Overlay Orchestrator designs, BGP neighbor relationships are formed across the overlay tunnel interfaces / overlay endpoints , not directly on the raw underlay interfaces (port1/port2) and not on the advertised LAN interface (port5). Therefore, options A and D are not valid conclusions from what is shown.

So, the two correct conclusions are B and C .